Structural materials which are used at high temperatures, such as members for semiconductor manufacturing apparatuses, members for heating furnaces, etc., are required to have heat resistance, chemical stability, strength, and so on. As those materials, graphite is widely used. Nonetheless the graphite is excellent in heat resistance, chemical stability, and strength, it is not an universal material in view of the facts that it is weak in a reaction with oxygen so that it is liable to be oxidized and consumed, it is soft so that it is liable to be worn, and it has reactivity with hydrogen, ammonia, or the like at high temperatures, and so on.
In order to compensate for those weaknesses of the graphite, a ceramic composite material in which a ceramic coating, such as SiC, etc., is formed on a surface of the graphite is widely used. In such a ceramic composite material, since the graphite and the ceramic coating are a heterogeneous material from each other, it is required to firmly bond the ceramic coating and the graphite base material to each other, thereby securing resistance to thermal shock.
In order to solve the foregoing problem, Patent Document 1 describes a SiC-coated graphite member that is a graphite member in which a SiC coating is cladded on a surface of a graphite base material by the CVD method, wherein the graphite base material has pore properties of an average pore diameter of 0.4 to 3 μm and a maximum pore diameter of 10 to 100 μm, an occupancy rate of SiC in a surface layer part of the graphite base material at a depth of 150 μm from the surface of the graphite base material is 15 to 50%, and an average crystal particle diameter of the SiC coating is 1 to 3 μm.